Prevalence of somatoform disorders in a psychiatric population: an Italian nationwide survey. Italian Collaborative Group on Somatoform Disorders.

The survey involved 50 centres comprising both hospital and community psychiatric care services throughout Italy. Overall, 2620 patients were recruited, and of those 2002 (76%) completed the Somatoform Disorders Schedule (SDS), a CIDI-derived interview. The NOS somatoform disorders (SDs) diagnosis appeared to be the most common (60%) (and they showed the highest number of co-morbid diagnoses), followed by pain disorders (8%). The prevalence of undifferentiated somatoform and hypochondriactal disorders was 1.6%: older age groups showed a tendency towards higher rates of the latter. In general, the study found that a significant percentage of patients with SDs are referred to psychiatric services, but mainly because of other psychopathological problems: in fact, somatic complaints are cross-sectionally present in different psychiatric nosological categories. This study also emphasizes some limitations of the current classification of SDs.